Biodegradable polymers have become increasingly important for a variety of biomedical applications including biomedical implants, such as stents, and coatings applied to those implants, tissue engineering scaffolds, and soft-tissue adhesives. Segmented polyurethane elastomers in particular have come into wide use as biomaterials due to their superior mechanical properties and chemical versatility. PCT International Application Publication No. WO 2004009227 describes certain degradable polyurethane compositions for use as tissue engineering scaffolds. U.S. Pat. No. 6,306,177 (Felt et al.) describes curable polyurethane compositions comprising a plurality of parts capable of being sterilized, stably stored, and mixed at the time of use in order to provide a flowable composition upon mixing that is sufficiently flowable to permit it to be delivered to the body by minimally invasive means. U.S. Patent Application Publication No. 20050013793 (Beckman et al.) also describes degradable polyurethanes for e.g., tissue engineering and particularly for bone repair and replacement. U.S. Pat. No. 4,829,099 (Fuller et al.) describes certain absorbable polyisocyanates for use as surgical adhesives. U.S. Pat. Nos. 8,002,843 and 7,985,414 (Knaack et al.) describe a biodegradable polyisocyante (such as lysine diisocyanate) with an optionally hydroxylated biomolecule to form a degradable polyurethane. U.S. Pat. No. 7,964,207 (Deslaurier et al.) describes osteoconductive polyurethane compositions having mechanical properties consistent for use in bone repair.
For certain applications, in addition to being biodegradable, it is advantageous for a surgical implant to be moldable or formable, for example to optimize its placement at the implant site and/or to fill voids in hard or soft tissue at the site of implantation. U.S. Pat. No. 8,431,147 and U.S. Pat. No. 8,282,953 (Warsaw Orthopedic, Inc) describe malleable implants containing demineralized bone matrix. The “malleable implant compositions” described in these patents contain a particulate solid collagen material and a particulate solid DBM material along with a liquid carrier that comprises an aqueous gel of alginate. Alginate/DBM based compositions are also described in U.S. Pat. No. 8,506,983 (Warsaw Orthopedic, Inc). US 20130236513 (Guelcher et. al, Vanderbilt Univ.) describes polyurethane composites that, in some aspects, may be “processed” as a reactive liquid that subsequently cures in situ to form a solid composite.